FIFO程序调度源代码

#define TRUE 1
#define FALSE 0
#define INVALID -1
#define NULL 0
#define total_instruction 320 /*指令流长*/
#define total_vp 32  /*虚页长*/
#define clear_period 50  /* 清零周期*/
typedef struct  /* 页面结构*/
{
    int pn,pfn,counter,time;
}pl_type;
pl_type pl[total_vp];
struct pfc_struct{
  int pn,pfn;
  struct pfc_struct *next;
};
typedef struct pfc_struct pfc_type;
pfc_ type pfc[total_vp],*freepf_head,*busypf_head,*busypf_tail;
int diseffect,a[total_instruction];
int page[total_instruction],offset[total_instruction];
int initialize(int);
int FIFO(int);
int main(){
int s,i,j;
srand(10*getpid());
s=(float)319*rand()/32767/32767/2+1;
for(i=0;i<total_instruction;i+=4)
{
if(s<0||s>319)
{
printf("When i==%d,Error,s==%d\n",i,s);
exit(0);
}
a[i]=s;
a[i+1]=a[i]+1;
a[i+2]=(float)a[i]*rand()/32767/32767/2;
a[i+3]=a[i+2]+1;
s=(float)(318-a[i+2])*rand()/32767/32767/2+a[i+2]+2;
if((a[i+2]>318)||(s>319))
printf("a[%d+2],a number which is: %d and s==%d\n",i,a[i+2],s);
}
for(i=0;i<total_instruction;i++)
{
page[i]=a[i]/10;
offset[i][=a[i]%10;
}
for(i=4;i<=32;i++)
{
printf("--%2d page frames---\n",i);
FIFO(i);
}
return 0;
}
int initialize(total_pf)
int total_pf;
{
    int i;
    diseffect=0;
    for(i=0;i<total_vp;i++)
{
pl[i]pn=i;
pl[i].pfn=INVALID;
pl[i].counter=0;
pl[i].time=-1;
}
for(i=0;i<total_pf-1;i++)
{
pfc[i].next=&pfc[i+1];
pfc[i].pfn=i;
}
pfc[total_pf-1].next=NULL;
pfc[total_pf-1].pfn=total_pf-1;
freepf_head=&pfc[0];
return 0;
}
int FIFO(total_pf)
int total_pf;
{
int i,j;
pfc_type *p;
initialize(total_pf);
busypf_head=busypf_tail=NULL;
for(i=0;i<total_instruction;i++)
{
if(pl[page[i]].pfn==INVALID)
{
diseffect+=1;
if(freepf_head==NULL)
{
p=busypf_head->next;
pl[busypf_head->pn].pfn=INVALID;
freepf_head=busypf_head;
freepf_head->next=NULL;
busypf_head=p;
}
p=freepf_head->next;
freepf_head->next=NULL:
            freepf_head->pn=page[i];
pl[page[i]].pfn=freepf_head->pfn;
if(busypf_tail==NULL)
busypf_head=busypf_tail=freepf_head;
else
{
                busypf_tail->next=freepf_head;
                busypf_tail=freepf_head;
}
                freepf_head=p;
}
}
printf("FIFO:%6.4f\n",1-(float)diseffect/320);
return 0;
}